Current literature indicates that risk factors for eating disorders (ED) among native Americans are poorly understood. However, available evidence suggests that Native American adolescents females are one of the few groups at equal or greater risk for eating disorders than age-matched Caucasian females. Other recent research suggests that strenuous physical activity may be an independent risk factor for ED, although it remains unknown whether or not this applies to sub-clinical eating problems in adolescents. Still other evidence suggest that athletic involvement may either enhance or reduce the risk of ED depending on factors such as age, self-esteem, and level of competition. In light of this, the proposed study has two main goals: 1) to characterize the weight control practices of matched samples of Caucasian and Native American females at various ages pre-and post puberty and 2) to determine what aspects of athletic involvement may increase or reduce ED risks in each group. We expect athletic involvement to modify the risk for maladaptive weight control behaviors depending on ethnicity, type and level of athletic involvement, and the individual's level of sexual maturation. A proposed structural equation model (SEM) expressing specific hypotheses about various potential risk factors will be tested with data from each ethnic group. A cross-sectional survey will be administered to students in grades 5-10 from selected public schools in Billings and Hardin, MT. Measures of maladaptive weight control behavior, assessed by the Mc Knight risk factor Survey (MRFS-IV) and ED symptom profiles, assessed by the Eating Disorders Symptoms Checklist, will provide measures of the main dependent variables. As a supplement to goodness-of-fit analyses of the proposed model, a more exploratory regression-tree analytical approach will be used to examine which of several independent variables (predictors), including ethnicity, age, gender, maturational status, body shape satisfaction, height, weight, waist/hip ratio, and BMI, best predict specific ED symptoms. In addition of the survey data, a selected sample of the oldest students will participate in interviews designed to assess the onset-age and development history of specific weight control behaviors and physical activity patterns. A part of each interview will also assess differences in Native and Caucasian cultural views regarding eating weight-management and related issues. This work is a first attempt to our knowledge to compare age-matched Native American and Caucasian youth along these dimensions and should provide valuable data not currently available. Ultimately this work should inform decision-making regarding the advisability of specific types of athletic participation as interventions aimed at reducing the risk of eating disorders and/or obesity.